Higher Nitrate Air Pollution In Central Wash.

Researchers have found the source of an unusual pocket of air pollution in central Washington. Tiny particles from large agricultural operations mix with vehicle exhaust. That creates nitrate pollution.

Nitrate air pollution is higher in the Yakima Valley than many other places in Washington. These fine particulates are so tiny that you can’t see them. But if you breathe them in at high concentrations, they can cause heart and respiratory problems.

Researchers found three things are needed to create the nitrate pollution: ammonia from agriculture, car exhaust and cold, humid temperatures.

Jeff Johnston is with the state Department of Ecology.

“It’s formed in the air, so it’s going to be harder to control,” Johnston said. “So it’s more complicated to control than other sources.”

Other sources like wood-burning stoves. That’s what causes most air pollution in central Washington.

Johnston said fine particulate pollution in the Yakima Valley comes in just under the Environmental Protection Agency’s air quality standards.